In the recent years, aside from a capacity increase, size reduction and thinning of a semiconductor package are under progress for installing the same to a limited space. As the semiconductor package, there is a multilayer structure in which a plurality of semiconductor chips is laminated in one package. Under such a circumstance, due to a thickness of the semiconductor chips being very thin, a crack is easily generated in the semiconductor chips. The crack may occur by a load being accumulated at a portion with a foreign matter, in a case where a semiconductor chip is mounted on a stage on which the foreign matter is adhered.
The crack generated in the semiconductor chip is detected by an appearance observation inspection using a magnification observation and recognition camera, for example. For example, a method in which a surface of the semiconductor chip mounted on the stage is taken by the recognition camera, and image information obtained therefrom is processed is known. In this method, there is a case in which a contrast difference becomes small between the crack and a portion on a periphery thereof, when a resin layer is formed on the surface of the semiconductor chip. It becomes difficult to obtain an accurate inspection result by the determination on the crack becoming insufficient.
For example, a method in which infrared light is irradiated from a rear surface side of the semiconductor chip having the resin layer formed on its surface, and the crack is detected from a difference in reflected light is known. In this method, there is a case in which the contrast difference becomes small between the crack and the portion on the periphery thereof, when an adhering layer is formed on a rear surface of the semiconductor chip. It becomes difficult to obtain an accurate inspection result by the determination on the crack becoming insufficient. Further, a structure of the semiconductor manufacturing device becomes complicated by providing a facility to irradiate with the infrared light from the rear surface side.
In a case where the crack generated in the semiconductor chip is not detected before being packaged, and is determined as a defect for the first time upon an inspection of a finished product, that finished product is going to be dealt as a defective product. In this case, components other than the semiconductor chip in which the crack has occurred and manufacturing cost thereof are wasted. Further, a large number of defective products will be produced, due to the difficulty in specifying the cause of the crack.